1993 Fiscal Year Final Research Report Summary
Effect of CO_2 concentration on photosynthesis in deciduous broad-leaved tree species
| Project/Area Number |
03660150
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
林学
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| Research Institution | Niigata Univ. |
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Principal Investigator |
MARUYAMA Koohei Niigata Univ. Fac. of Agric., Professor, 農学部, 教授 (30018535)
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| Project Period (FY) |
1991 – 1993
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| Keywords | Photosynthesis rate / CO_2 concentration effect / Decidous broad-leaved tree species / Temperature effect / Water stress effect / Conductance |
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| Research Abstract |
(1) Effects of CO_2 levels on net photosynthesis of single leaf in several deciduous broad-leaved tree species : P_n and the saturated PAR were generally increased with inceasing CO_2 levels in most species tested. From the light-photosynthesis curves, we classified fagus crenate(Fc) as low CO_2-weak light use type, Zelkova serrata(Zs) as high CO_2-weak light use type, Alnus firma(Af) as high CO_2-strong light use type, and Ginkgo biloba(Gb) as high CO_2-intermediate type.
(2) Effects of short-term CO_2 levels and temperatures on the photosynthesis and respiration of some deciduous broad-leaved tree species seedlings : Temperature-photosynthesis curves in strong light showed a distinct optimum curves. The optimum temperatures were found at 15-35ﾟC, the values shifted from low to high temperatures with increasing CO_2 levels. Among five species, Af & W.hortensis(Wh), shrub species, had a higher P_n and the broad optimum ranges. Fc, Qc & Gb, tree species, exhibited a contrasting pattern. (3) Effects of CO_2 levels on a leaf photosynthesis in Qc, Q.dentata(Qd) and Wh seedlings : CO_2 levels that saturated P_n were found above 900ppm in 2Quercus species, and 600ppm in Wh. The water use efficiency enhanced with higher CO_2 levels irrespective of species.
(4) Effects of high CO_2 levels and water stress on gas exchange in Alnus firma : The rates of Pn, Tr and g_s decreased with increasing water stress. The critical water potentials were found at -12, -10, -8 bars, respectively. COn_2 effects were observed in Pn and g_s under well-watered conditions above -8 bar water potentials.
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